The GISS Surface Temperature (GISTEMP) analysis provides a measure of the changing global surface temperature with monthly resolution for the period since 1880, when a reasonably global distribution of meteorological stations was established. The input data that the GISTEMP Team use for the analysis, collected by many national meteorological services around the world, is the adjusted data of the Global Historical Climatology Network (GHCN) Vs. 3 (this represents a change from prior use of unadjusted Vs. 2 data) (Peterson and Vose, 1997 and 1998), United States Historical Climatology Network (USHCN) data, and SCAR (Scientific Committee on Antarctic Research) data from Antarctic stations. Documentation of the basic analysis method is provided by Hansen et al. (1999), with several modifications described by Hansen et al. (2001). The GISS analysis is updated monthly, however CDIAC’s presentation of the data here is updated annually.
The GISTEMP Web site is the most comprehensive and direct source of information for these data. Users are strongly encouraged to visit the NASA GISS Web site, where you can specify input for making customized maps, graphs, and subsets of the data, in addition to learning many more interesting details about these data and their analysis. Here, we seek to give users a brief, high-level overview of the GISTEMP analysis and provide you with convenient access to the main time series graphs, data tables, and related references. This brief summary of the methods employed by the GISTEMP Team in their analysis is mostly borrowed from their NASA GISS Web pages. Significant updates to the GISTEMP Team methods are described in a 2010 paper. They describe the use of satellite-observed nightlights to identify measurement stations located in extreme darkness and adjust temperature trends of urban and peri-urban stations for non-climatic factors, verifying that urban effects on analyzed global change are small. The paper compares alternative analyses, and addresses questions about perception and reality of global warming. The GISTEMP Team modifies the GHCN/USHCN/SCAR data in two steps to get to the station data on which all their tables, graphs, and maps are based: in step 1, if there are multiple records at a given station, these are combined into one record; in step 2 they adjust the non-rural stations in such a way that their long-term trend of annual means matches that of the mean of the neighboring rural stations. Records from urban stations without nearby rural stations are dropped.
Global Annual Temperature Anomalies (Land), 1880-2014 Global Annual Temperature Anomalies (Land+Ocean), 1880-2014 Hemispheric Temperature Anomalies (Land+Ocean), 1880-2014 Global Annual Temperature Anomalies (Land+Ocean) for three latitude bands, 1900-2014